In papermaking industry, inorganic fillers are widely used for the purpose of improving opacity, brightness, printability, uniformity and dimensional stability. They are also useful for production costs and energy savings. In the past, inorganic fillers in papermaking industry only focused on micro-scale but recently, new trials on nano-powdered technology are applying. Even nano-powdered fillers are rapidly utilized for improving the optical and surface properties in coating and surface sizing, there still have some problems in wet-end process due to poor dispersibility and retention. In this study, nano-particled calcium carbonate was produced by milling the PCC and its applicability between micro sized and nano sized calcium carbonated was compared in wet-end process, and finally the sheet properties were evaluated. Nano-PCC was not retained in sheet structure without applying retention system, but with retention system nano-powdered PCC was absorbed on fiber surface with expanding the fiber networks. The application of PAM-bentonite system has resulted in high ash retention and bulky structure for copier paper, and good optical properties in brightness and opacity. However, it required to solve the weakness of low tensile property due to interruption of hydrogen bonding by nano fillers.

The objective of this study was to investigate the beating properties of two types of cotton pulps such as "cotton lint mixed pulp" and "cotton linter pulp". In order to improve refining characteristics, the effects of carboxymethyl-cellulose (CMC) pre-treatment, mixing ratio changes of cotton lint mixed pulp and cotton linter pulp, and refining load changes were analyzed. In mill application, it was possible to improve the refining characteristics and maintained the strength properties of the paper by applying increasing ratio of cotton linter pulp mixing and controlling the refining methods.

As a part of the study on manufacture of low density paper by organic bulky agent treatment, the effects of cationic fatty acid bulky agent on physical and optical properties of handsheets were elucidated. The research on change of physical and optical properties of paper samples according to bulky agent concentration, pulp type, and pulp combination were carried out. The results demonstrated that an increase of the concentration of cationic fatty acid bulky agent was proportional to an increase of the bulky properties of paper samples while tensile strength decreased. Also, the more the treated concentration of cationic fatty acid bulky agent increased, the more the ISO brightness of paper samples decreased while the opacity increased. The effectiveness of bulky agent with softwood bleached kraft pulp (SwBKP) was higher than that with hardwood bleached kraft pulp (HwBKP). In addition, the effectiveness with mixed pulps was higher than that with single pulp.

We studied the green synthesis and antibacterial activity of paper coated with chitosan-silver (Ag) green nanocomposites for packaging applications. Green synthesis of Ag nanoparticles (AgNPs) was achieved by a chemical reaction involving a mixture of chitosan-silver nitrate () in an autoclave at 15 psi, , for 30 min. AgNPs and their formation in chitosan was confirmed by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). As-prepared chitosan-AgNPs composite materials were coated on manila paper using Meyer rod. Surface morphology and Ag contents in coating layer were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). The mechanical properties such as tensile strength and elongation were significantly affected by coating with chitosan-AgNPs. The antibacterial test of coated paper was performed qualitatively and quantitatively against Escherichia coli (E. coli). It was shown to be effective in suppressing the growth of E. coli with increasing Ag contents on the surface of coated paper and more than 95 R (%) of antimicrobial rate was obtained at chitosan-AgNPs coated papers.

The crystallinity and molecular weight of cotton linter need to be controlled to be more easily dissolved in NMMO during manufacture of clothing fabrics. Electron beam irradiation and sulfuric acid treatment were used as pre-treatment to reduce molecular weight of cotton linter more efficiently, and after the pre-treatment, peroxide bleaching was followed in alkaline condition. After those processes, the crystalline indices of the cotton linters were measured by XRD method, and other properties such as their alpha cellulose contents and degree of polymerization were measured. It was found that the crystallinity index of cotton linter was decreased as the irradiation of electron beam increased while increased as the dose of sulfuric acid increased. These results strongly suggested that electron beam damaged the crystalline structure of the cellulose directly while sulfuric acid dissolved mostly non-crystalline area of the cellulose structure.

This research were aimed at developing starches which have high preservability and high bonding strength from corn starch, modified cationic and oxidized corn starches, as compared to the fermented wheat starch. On the lining that attaching the base paper on the back of the work with paste, the coating weight was determined by the solid contents of the paste rather than the viscosity of paste. Adhesive strength and stiffness were also determined by the solid contents of the paste. Corn starch had lower solid contents, higher viscosity, and higher adhesive strength than other starches. In the iodine stain to the surface of peeled base paper off, paste deeply penetrated into the traditional Hanji than modern Hanji. And oxidized starch paste deeply penetrated into the paper layer than the cationic starch.

Effects of artificial thermal aging on color variations of various commercial papers (fine paper, coated paper, newsprint and filter paper) were investigated. With thermal aging at , most of papers showed a special trend in plane: the (red-green) values of the samples were initially reduced (heading to - side) and after a turning point they increased to + side while the (blue-yellow) values were kept increased to + side (yellowing of paper). Different papers had different turning points for value. The filter paper consisted of a pure chemical pulp and the copy paper with OBA (optical brightening agent) showed the latest turing points. In addition, the papers without OBA showed less reduction in brightness compared with that with OBA, suggesting that OBA could adversely influence the brightness stability during thermal aging.

The application of conifer leave to the papermaking process as a functional organic filler was investigated in this study. The powder of the conifer leave after hot water extraction for the functional extract, such as phytoncide, was applied to OCC stock. The comparison between the commercial wood flour and the conifer leave powder as organic filler for OCC paper were conducted with various wet pressing conditions. The amount of the water removal by the wet pressing process and the bulk of handsheet were increased by the addition of the wood flour and the conifer leave powder, although the tensile strength was decreased. At the higher pressure condition of the wet pressing, the wet pressing efficiency was greatly increased by the wood flour and the conifer leave powder. There was a little difference in the performance of the wood flour and the conifer leave powder as an organic filler. Those results showed the conifer leave powder could be an alternative resource to the wood powder for papermaking organic filler.

Effects of alkali swelling of HwBKP (hardwood bleached kraft pulp) at a low concentration below 2 percent (based on the oven-dried weight of pulp) on handsheet properties were investigated. Swelling treatment of HwBKP was performed at various low NaOH concentrations with/without beating. Then, the changes in handsheet properties were evaluated in terms of bulk, optical and strength properties. It was found that bulk was slightly increased when the alkali concentration was increased. When the pulp was only swollen without beating, paper optical and strength properties was slightly decreased or not changed with alkali concentration. When the pulp was alkali-swollen after beating, paper strength and opacity showed almost no changes while brightness was increased. When the pulp was beaten after NaOH swelling, alkali concentration showed almost no effect on brightness and opacity of paper. Paper strength was slightly decreased with alkali concentration, suggesting that alkali pretreatment before refining could adversely affect refining efficiency.

Preventive conservation is one of most important issues in the field of conservation for paper-records. Many researchers have been studied environmental factors such as effects of humidity, temperature, biological attack and air pollutants. Air pollutants strongly associated with oxidative and hydrolytic degradation of cellulose. It is important to control air pollutants in storage environment to improve stabilities of conservation environment. Four paper samples have been analyzed for their accelerated aging characteristics by air pollutants, sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide. Physical and optical properties and weight molar masses(Mw) showed that interactions between air pollutants and paper sample. Nitrogen dioxide, ozone caused severe damage to cellulose in paper by hydrolytic and oxidative decompositions during aging.

The disposal of the paper mill sludge and the paper mill sludge ash become more important issue, because the environment regulation becomes more strict. In this study, the new mulching system was developed by using the paper sludge ash. The soil surface hardening mechanism for mulching with paper sludge ash, red clay and coal ash was evaluated. Since the CaO in the paper sludge ash provided the harden structure with water, the surface hardening mulching structure could cover the field surface and prevent the germination of weeds. More than 50 w.t.% of red clay and 10 w.t.% of paper sludge ash were required to create the solid soil surface structure for mulching. The field test with the new soil surface hardening mulching system for three months showed the generation of weeds could successfully be inhibited by the system.

The packaging with environment-friendly materials become more important issue since the concern for the environment and the disposal of waste such as the packaging materials has increased. Although the paper based packaging such as corrugated box are widely used as a typical environment-friendly packaging stuff, the heat insulation properties of paper packaging did not get many attention. In this study, the heat insulation properties of paper were deeply evaluated to improve the functional properties as packaging material of the cold storage goods. The simple device for evaluating the heat insulation of paper product was developed. Subsequently, the changes in the heat insulation depending on the paper structure and the addition of the inorganic fillers were investigated by using the instrument. The higher basis weight and the less beating time resulted in the bulkier structure and the less efficiency of heat transfer. The addition of the perlite powder as a filler resulted in the great increase in the heat insulation, although the addition of the calcium carbonate decreased the heat insulation potential of paper.